Towards Picogram Detection of Superparamagnetic Iron-Oxide Particles Using a Gradiometric Receive Coil

Superparamagnetic iron-oxide nanoparticles can be used in a variety of medical applications like vascular or targeted imaging. Magnetic particle imaging (MPI) is a promising tomographic imaging technique that allows visualizing the 3D nanoparticle distribution concentration in a non-invasive manner. The two main strengths of MPI are high temporal resolution and high sensitivity. While the first has been proven in the assessment of dynamic processes like cardiac imaging, it is unknown how far the detection limit of MPI can be lowered. Within this work, we will present a highly sensitive gradiometric receive-coil unit combined with a noise-matching network tailored for the measurement of mice. The setup is capable of detecting 5 ng of iron in vitro at 2.14 sec acquisition time. In terms of iron concentration we are able to detect 156 {\mu}g/L marking the lowest value that has been reported for an MPI scanner so far. In vivo MPI mouse images of a 512 ng bolus at 21.5 ms acquisition time allow for capturing the flow of an intravenously injected tracer through the heart of a mouse. Since it has been rather difficult to compare detection limits across MPI publications we propose guidelines improving the comparability of future MPI studies.Comment: 15 Pages, 7 Figures, V2: Changed the initials of Author Kannan M Krishnan, added two citations, corrected typo

Diagnosis and Decision-Making in Telemedicine

This article provides an analysis of the skills that health professionals and patients employ in reaching diagnosis and decision-making in telemedicine consultations. As governmental priorities continue to emphasize patient involvement in the management of their disease, there is an increasing need to accurately capture the provider–patient interactions in clinical encounters. Drawing on conversation analysis of 10 video-mediated consultations in 3 National Health Service settings in England, this study examines the interaction between patients, General Practitioner (GPs), nurses, and consultants during diagnosis and decision-making, with the aim to identify the range of skills that participants use in the process and capture the interprofessional communication and patient involvement in the diagnosis and decision-making phases of telemedicine consultations. The analysis shows that teleconsultations enhance collaborative working among professionals and enable GPs and nurses to develop their skills and actively participate in diagnosis and decision-making by contributing primary care–specific knowledge to the consultation. However, interprofessional interaction may result in limited patient involvement in decisionmaking. The findings of this study can be used to inform training programs in telemedicine that focus on the development of effective skills for professionals and the provision of information to patients

Voxel-Based Similarity Measures for Medical Image Registration in Radiological Diagnosis and Image Guided Surgery

Registration of images is a key technique for numerous medical applications from diagnosis to image guided therapy. In the present paper we focus on gray-value based registration methods. Of special interest is the so-called similarity measure which must be optimized. It is the intention of the paper to emphasize the fact that a successful registration requires a similarity measure that is carefully chosen with respect to the underlying medical application. Two single-modality examples are presented in the paper, i.e. the diagnostic tool of digital subtraction angiography and an intervention guidance under X-ray fluoroscopic control. We discuss new similarity measures, i.e. the class of one-dimensional hi stogram based measures and the pattern intensity, designed for these applications and compare them with frequently used measures like the cross-correlation function , cross-structure function and deterministic sign change criterion. It is demonstrated that the results obtained with the new measures are superior to the results obtained with the latter mentioned ones

Self-assembly of magnetic iron oxide nanoparticles into cuboidal superstructures

This chapter describes the synthesis and some characteristics of magnetic iron oxide nanoparticles, mainly nanocubes, and focus on their self-assembly into crystalline cuboids in dispersion. The influence of external magnetic fields, the concentration of particles, and the temperature on the assembly process is experimentally investigated

Magnetic resonance imaging of adipose-derived adult stem cells labelled with superparamagnetic iron oxide nanoparticles

The application of mesenchymal stem cells (MSCs) represents a new promising approach for treating neurodegenerative diseases. Recently, considerable attention has been paid to adipose-derived adult MSC (ADAS), thanks to the easy availability of adipose tissue and to the possibility of autologous cells transplantation. Any possible application of therapies based on ADAS in the clinics cannot occur without elucidation of their homing. Superparamagnetic iron-oxide nanoparticles (NPs) can be used to label and track cells in vivo via Magnetic Resonance Imaging (MRI